1. Field of the Invention
The present invention relates to a system that supports a purchase or a production of a product, and particularly relates to a system that supports a purchase or a production of a product based on a history of a sold amount and a history of a supplied amount of the product.
2. Description of the Related Art
In recent years, in a type of business such as eating and drinking places or restaurants, retail businesses, and distribution industries, items of products for sale has been increasing with diversification of demands. In such types of businesses, when an amount of purchase or an amount of production is determined based on experience and perception of a person in charge, it is concerned that dead stock or sold out may occur and thus it causes the loss and the decrease of profit. Therefore, it is desirable that a computer system predicts a future amount of sale based on, for example, actual data of a past sold amount and determines an appropriate amount of purchase or amount of production.
For example, if the probability distribution of a sold amount can be obtained as a prediction of a future sold amount, it will be possible to determine an amount of purchase by solving a problem conventionally known, i.e., maximization of an expected profit (refer to Non-Patent Documents 1 to 3). In fact, there has been conventionally provided a proposal of a system in which an amount of purchase or an amount of production may be computed based on a prediction of a future sold amount (refer to Patent Documents 1 to 7).
[Non-Patent Document 1]
Nobuo Saji: “Operations research theory and practice”, baifu-kan, pp 170-172, 1963
[Non-Patent Document 2]
Fumihiro Higashihara, Atsushi Saito: Optimal order amount of rice-balls in a convenience store, http://www.seto.nanzan-u.ac.jp/msie/gr-thesis/ms/2003/sawaki/sawaki.html
[Non-Patent Document 3]
Special Committee of Statistical Education: Problem of a news vendor, http://stat.sci.kagoshima-u.ac.jp/˜cse/contents/orency/doc/p182.html
[Non-Patent Document 4]
S. L. S. Jacoby, J. S. Kowalik, J. T. Pizzo: “Interative Methods for Nonlinear Optimization Problems”, Prentice-Hall, Inc., 1972
[Non-Patent Document 5]
Magnus Hestenes: “Comjugate Direction Methods in Optimization”, Springer-Verlag, 1980
[Patent Document 1]
Japanese Unexamined Patent Publication No. Heisei 8-55161
[Patent Document 2]
Japanese Unexamined Patent Publication No. Heisei 10-48008
[Patent Document 3]
Japanese Unexamined Patent Publication No. 2002-149780
[Patent Document 4]
Japanese Unexamined Patent Publication No. 2003-256524
[Patent Document 5]
Japanese Unexamined Patent Publication No. 2004-287759
[Patent Document 6]
Japanese Unexamined Patent Publication No. Heisei 9-73491
[Patent Document 7]
Japanese Unexamined Patent Publication No. 2003-256635
[Patent Document 8]
Japanese Unexamined Patent Publication No. 2004-62693
[Patent Document 9]
Japanese Unexamined Patent Publication No. 2004-1184429
[Patent Document 10]
Japanese Unexamined Patent Publication No. Heisei 5-314094
[Patent Document 11]
Japanese Unexamined Patent Publication No. 8-279013
According to the techniques described in Patent Documents 1 to 5, a predicted value of a sold amount is computed as a constant. Therefore, a profit becomes large if the predicted value is equal to an actual sold amount, whereas a profit becomes extremely small if the predicted value is different from an actual sold amount. That is, it can be considered that in comparison with the technique for computing a predicted value of a sold amount as probability distribution, the accuracy of prediction declines, causing a decrease in an expected profit. Meanwhile, according to the techniques described in Patent Documents 6 and 7, a predicted value of a sold amount is computed as probability distribution. However, these documents do not describe how to compute a predicted value of a sold amount based on actual data on past sold amounts. Therefore, even in these techniques, a predicted value of a sold amount is computed depending on experience and perception of a parson in charge.
It can be also considered to use distribution of a past sold amount without modification, as the probability distribution of a future sold amount by means of the actual data of the past sold amount. However, if considering so-called “absence of goods”, it is considered that a past sold amount is restricted by a stock amount at that time and thus potential demand of a consumer is not properly reflected. That is, when a past sold amount is used without modification as a predicted value of a future sold amount, there is predicted a sold amount less than actual demand. For this reason, by repeating such a prediction, there has been a problem that an amount of purchase goes down in sequence and thus a scale of business comes to shrink.
Next, Patent Documents 8 to 11 will be cited as reference techniques. According to the technique described in Patent Document 8, there is provided a proposal of a technique for supplying a prediction of purchase of the product and other information in considering whether or not the product should be reserved. In this technique, it is described that “probability information” is used for a prediction of purchase (claim 3), however, it is not described how this “probability information” is used for computing a prediction of purchase. Therefore, it is considered that there is not provided a solution of a problem that actual demand cannot be accurately predicted due to generation of “absence of goods”.
The technique described in Patent Document 9 is intended for promoting efficiency of production planning in a production line or the like. According to this technique, a future demand is predicted based on demand actual data in the past, and a production planning is streamlined to decrease a supplied amount insufficient for the predicted demand. However, in this document, it is not described how to realize future demand prediction, either. Also, Patent Document 10 describes a technique for predicting a future sold amount based on the past data. This technique is for predicting a trend indicating periodic variation of an achievement of sale to predict a future sold amount along the trend, and it is an objective to improve the accuracy of prediction of the trend. From a macro-perspective, the trend is effective. However, in a micro-problem in which individual shops are addressed, if there is no product available in a shop, a consumer goes to another shop to buy the product, and therefore the sale to be essentially realized by the shop will move to another shop. In other words, since in this technique, there is not provided a consideration of any restriction on a sold amount by a purchase amount, the technique is not effective from the viewpoint of an individual shop. The technique described in Patent Document 11 measures the opportunity loss with an amount of money based on conception of costs incurred by “absence of goods.” However, in this technique, this amount of the opportunity loss is not particularly used to predict a future demand.
Therefore, it is an objective of the present invention to provide a system, a method and a program product, which can solve the problems stated above. This objective can be achieved by combining characteristics described in independent claims in the scope of the claims. Dependent claims provide specific examples that are further beneficial in the present invention.